The present invention relates to a polypeptide having neural growth inhibitory action.
Amidst the growing number of elderly people in our society, the issue of senile dementia is attracting considerable concern, and numerous efforts have been made for its prevention and treatment. In particular, since a senile dementia known as Alzheimer's disease frequently occurs in presenium (age 50-60), elucidation of its cause and establishment of a method of treatment are greatly desired.
According to findings obtained thus far, Alzheimer's disease is considered to be an organic disease having both pathological characteristics such as senile plaques and neurofibrillary degeneration, as well as clinical characteristics such as progressive dementia. In addition, acceleration metabolism and abnormal regeneration of neuron are involved in this disease.
A novel protein having neural growth inhibitory action (growth inhibitory factor, GIF) was separated and found during the course of research on the brain components of Alzheimer's patients, which exists in the brains of normal persons but disappears from the brains of Alzheimer's patients, along with a process for producing said GIF using genetic engineering techniques, were respectively disclosed in Japanese Provisional Unexamined Patent Application (KOKAI) No. 18100/1992, European Unexamined Patent Application No. 458,673 and PCT Patent Publication No. WO92/10568.
Since it would be possible to study the GIF action if detailed information were obtained concerning its active site, the potential for use as a pharmaceutical drug would be greatly increased.
In addition, if it is possible to use a smaller polypeptide containing the active site as a pharmaceutical drug, it would be more advantageous in terms of production and preparation as a pharmaceutical preparation.